When scientists talk about the cryosphere, they mean the places on Earth where water is in its solid form, frozen into ice or snow. Read more ...

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Tag Archives: sea ice

The ability to view data interactively adds convenience to dynamic data analysis. While static graphs and images are informative, interactive tools allow users to view and analyze data on-the-fly. Readers of our Arctic Sea Ice News and Analysis blog enjoy daily updates on sea ice extent, but some wanted to see data from specific days or years that weren’t provided in the static graphs. Behold Charctic.

NSIDC now offers a new Web site, Satellite Observations of Arctic Change (SOAC) with interactive maps of the Arctic based on NASA satellite and related data. The site allows users to explore how conditions in the Arctic have changed over time. SOAC is available at http://nsidc.org/soac.

This sample image from Satellite Observations of Arctic Change shows near-surface air temperature anomalies for October 2012, along with a bar chart of anomalies over time.

Users may animate a time series, zoom in or out, and view a bar graph of anomalies over time. Links to the source data and documentation are also included. Additional pages provide brief scientific discussion, and overviews of the scientific importance of these data.

More data types and extended temporal coverage may be added in the future, if interest warrants and funding continues. SOAC was developed with support from NASA Earth Science (http://science.nasa.gov/earth-science/).

Back in the 1960s, technology to process massive amounts of data and imagery did not exist. Advancements in technology now allow for the processing of film into a digital format. The Nimbus Data Rescue Project set out on a techno-archeological mission to convert data and images from the NASA Nimbus 1 and 2 satellites that were developed on film into a more manageable digital format. These data extend the satellite record back in time providing the earliest satellite data of polar sea ice extent.

The Nimbus Advanced Vidicon Camera System Visible Imagery L1, HDF5(NmAVCS1H) is the first data set publicly available from the Nimbus Data Rescue Project. NmAVCS1H consists of black-and-white Advanced Vidicon Camera System (AVCS) images that were acquired by the Nimbus 1 satellite during September 1964 and by Nimbus 2 from May to August 1966. NSIDC researchers and staff scanned the images from archival rolls of 35-mm, black-and-white film. Each HDF5-formatted data file contains an array of 8-bit grayscale values, estimates of the latitude and longitude for each pixel, a grayscale calibration map, and a non-data/data quality mask. Browse images are also available.

New data regarding snow, sea ice, Greenland surface melt and more will be coming soon to NSIDC. The NASA Making Earth System Data Records for Use in Research Environments (MEaSUREs) program is dedicated to the development of consistent global and continental scale data records related to earth science. NSIDC currently archives six data sets from the MEaSUREs program, and the additional data sets will be available in the near future.

NSIDC’s sea ice concentration data are used by scientists and students, journalists and advisers. The range of possible uses for the data is as varied as the data users themselves. The biggest hurdle encountered by many users is simply learning how to initially read and display the data. Here are some tips on how to get started.

The “Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS Passive Microwave Data” are distributed in gridded binary format. NSIDC provides IDL routines to ingest and read the data. These tools can be found at the Polar Stereographic Tools Web page.

However, if you are unfamiliar with IDL, there are other options that you can use. First of all, you may be interested in downloading the data via the Polaris search and order interface. This Web tool allows you to download the data in GeoTIFF or NetCDF formats. It also allows you to make spatial and temporal constraints on the data as well as change the output projection.

If you are interested in importing the data to ArcGIS, you can either use the GeoTIFF files downloaded from Polaris (see above), or you can perform a few steps to import the native binary files. In order to do this, you will need to rename the files, create a header file for the data, and use ArcToolbox to transform the files to a different format. Instructions detailing how to do this can be found in this Online Support article.